<!DOCTYPE html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Gravity</title>
<link rel="manifest" href="/site.webmanifest">
<link rel="stylesheet" href="/css/bootstrap.min.css" crossorigin="anonymous">
<link rel="stylesheet" href="/css/style.css">
<link rel="preconnect" href="https://fonts.gstatic.com">
<link href="https://fonts.loli.net/css2?family=Anonymous+Pro:ital,wght@0,400;0,700;1,400;1,700
&family=Noto+Serif+SC:wght@300;400;500;600;700&display=swap" rel="stylesheet">
<script src="https://apps.bdimg.com/libs/jquery/1.10.2/jquery.min.js"></script>
<style>
* {
margin: 0;
padding: 0;
width: 100%;
height: 100%;
overflow: hidden;
}
.btn {
width: auto;
height: auto;
}
body {
background: radial-gradient(rgb(235, 235, 235), floralwhite);
padding: 0;
}
</style>
</head>
<body>
<a class="btn btn-default" href="/" onmouseenter="alert('单击屏幕添加元素。\n所有元素互相吸引，鼠标亦有引力。');$('.btn').hide()"
style="position:fixed"><span class="glyphicon glyphicon-question-sign" aria-hidden="true"></span></a>
<canvas id="canvas" onclick='init(10)' width="500" height="500"></canvas>
</body>
<script>
const LOST = 0.3;
var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');
var g = [];
const MAX_MASS = 3000;
const PLANET_COUNT = 300;
const FRAGMENT_COUNT = 100;
const FRAGMENT_SPEED = 20;
const MAX_SPEED = 8;
const G = 0.5;
var maxLineLength = 45;
const DEFAULT_MASS = 20;
const LOCK_TIME = 50;
const COLOR = '#333';
const LINE_COLOR = '#2344';
const MOUSE_MASS = 100;
var mousepoint = { x: 0, y: 0 };
window.AudioContext = window.AudioContext || window.webkitAudioContext;
if (!window.AudioContext) {
console.log('当前浏览器不支持Web Audio API');
}
var audioCtx = new AudioContext();
var arrFrequency = [196.00, 220.00, 246.94, 261.63, 293.66, 329.63, 349.23, 392.00, 440.00, 493.88, 523.25, 587.33, 659.25, 698.46, 783.99, 880.00, 987.77, 1046.50];
function init(count) {
if (g.length > 300) return;
var w = canvas.clientWidth;
var h = canvas.clientHeight;
for (var i = 0; i < count; i++) {
g.push({ x: Math.random() * w, y: Math.random() * h, mass: DEFAULT_MASS, vx: Math.random() * 2 - 1, vy: Math.random() * 2 - 1, lock: 0 });
}
}
function fillRound(cx, cy, r, color) {
context.beginPath();
context.fillStyle = color;
context.arc(cx, cy, Math.sqrt(r) / Math.PI, 0 * Math.PI, 2 * Math.PI, true);
context.fill();
}
function drawLine(x1, y1, x2, y2, color) {
context.beginPath();
context.moveTo(x1, y1);
context.strokeStyle = color;
context.lineTo(x2, y2);
context.stroke();
}
function collide() {
for (var i = 0, count = g.length; i < count; i++) {
for (var i1 = 0; i1 < count; i1++) {
if (i1 != i && g[i1]) {
if (g[i].lock > 0 && g[i1].lock > 0) continue;
if ((g[i].lock > 0 || g[i1].lock > 0) && Math.random() > 0.1) continue;
var r = Math.sqrt(Math.pow((g[i].x - g[i1].x), 2) + Math.pow((g[i].y - g[i1].y), 2));
if (r <= Math.max(Math.sqrt(g[i1].mass) / Math.PI + Math.sqrt(g[i].mass) / Math.PI) && g[i1].mass >= g[i].mass) {
var amplitude = Math.min(g[i1].mass, g[i].mass) / 1000 + (g[i1].mass + g[i].mass) / 2000;
g[i1].vy = (g[i1].mass * g[i1].vy + g[i].mass * g[i].vy) / (g[i1].mass + g[i].mass);
g[i1].vx = (g[i1].mass * g[i1].vx + g[i].mass * g[i].vx) / (g[i1].mass + g[i].mass);
g[i1].mass += g[i].mass;
g[i] = null;
var frequency = arrFrequency[Math.floor(Math.random() * 15)];
var oscillator = audioCtx.createOscillator();
var gainNode = audioCtx.createGain();
oscillator.connect(gainNode);
gainNode.connect(audioCtx.destination);
oscillator.type = 'sawtooth';
oscillator.frequency.value = frequency;
gainNode.gain.setValueAtTime(0, audioCtx.currentTime);
gainNode.gain.linearRampToValueAtTime(amplitude, audioCtx.currentTime + 0.01);
oscillator.start(audioCtx.currentTime);
gainNode.gain.exponentialRampToValueAtTime(0.001, audioCtx.currentTime + 1);
oscillator.stop(audioCtx.currentTime + 1);
break;
}
}
}
}
}
function explode() {
for (var i = 0, count = g.length; i < count; i++) {
if (g[i] && g[i].mass >= MAX_MASS) {
for (var i1 = 0; i1 < FRAGMENT_COUNT; i1++) {
g.push({
x: g[i].x + Math.random(),
y: g[i].y + Math.random(),
mass: g[i].mass / FRAGMENT_COUNT,
vx: FRAGMENT_SPEED * (Math.random() * 2 - 1),
vy: FRAGMENT_SPEED * (Math.random() * 2 - 1),
lock: LOCK_TIME * (Math.random() + 1)
});
}
var frequency = arrFrequency[Math.floor(Math.random() * 10)];
var oscillator = audioCtx.createOscillator();
var gainNode = audioCtx.createGain();
oscillator.connect(gainNode);
gainNode.connect(audioCtx.destination);
oscillator.type = 'sine';
oscillator.frequency.value = frequency;
gainNode.gain.setValueAtTime(0, audioCtx.currentTime);
gainNode.gain.linearRampToValueAtTime(1.3, audioCtx.currentTime + 0.01);
oscillator.start(audioCtx.currentTime);
gainNode.gain.exponentialRampToValueAtTime(0.001, audioCtx.currentTime + 10);
oscillator.stop(audioCtx.currentTime + 10);
g[i] = null;
}
}
}
canvas.onmousemove = function (event) {
var e = event || window.event;
mousepoint = { 'x': e.clientX, 'y': e.clientY };
}
function step() {
var w = canvas.clientWidth;
var h = canvas.clientHeight;
collide();
explode();
for (var i = 0, count = g.length; i < count; i++) {
if (g[i]) {
if (g[i].vx === NaN) {
g[i].vx = 0
}
if (g[i].vy === NaN) {
g[i].vy = 0
}
}
}
g = g.filter(e => e && e.x !== NaN && e.y !== NaN && e.vx !== NaN && e.vy !== NaN && e.mass !== NaN);
for (var i = 0, count = g.length; i < count; i++) {
if (g[i].x > w) {
g[i].x -= (g[i].x - w) * 2;
g[i].vx *= -(1 - LOST);
} else if (g[i].x < 0) {
g[i].x += g[i].x * -2;
g[i].vx *= -(1 - LOST);
}
if (g[i].y > h) {
g[i].y -= (g[i].y - h) * 2;
g[i].vy *= -(1 - LOST);
} else if (g[i].y < 0) {
g[i].y += g[i].y * -2;
g[i].vy *= -(1 - LOST);
}
fillRound(g[i].x, g[i].y, g[i].mass, COLOR)
for (var i1 = 0; i1 < count; i1++) {
if (i1 != i) {
var r = Math.sqrt(Math.pow((g[i].x - g[i1].x), 2) + Math.pow((g[i].y - g[i1].y), 2));
var f = r != 0 ? G * G * g[i1].mass / Math.pow(r, 2) : 0;
var dx = g[i1].x - g[i].x;
var dy = g[i1].y - g[i].y;
if (g[i].mass > 0) {
g[i].vy += f / r * dy;
g[i].vx += f / r * dx;
}
if (i1 > i && r <= maxLineLength) {
drawLine(g[i].x, g[i].y, g[i1].x, g[i1].y, LINE_COLOR)
}
}
}
//
var r = Math.max(1, Math.sqrt(Math.pow((g[i].x - mousepoint.x), 2) + Math.pow((g[i].y - mousepoint.y), 2)));
if (r > maxLineLength / 8) {
var f = r != 0 ? G * G * MOUSE_MASS / Math.pow(r, 2) : 0;
var dx = mousepoint.x - g[i].x;
var dy = mousepoint.y - g[i].y;
if (g[i].mass > 0) {
g[i].vy += f / r * dy;
g[i].vx += f / r * dx;
}
if (r <= maxLineLength) {
drawLine(g[i].x, g[i].y, mousepoint.x, mousepoint.y, LINE_COLOR);
}
}
//
var speedNow = Math.sqrt(Math.pow(g[i].vx, 2) + Math.pow(g[i].vy, 2))
if (speedNow > MAX_SPEED) {
g[i].vx = g[i].vx * MAX_SPEED / speedNow;
g[i].vy = g[i].vy * MAX_SPEED / speedNow;
}
g[i].x += g[i].vx;
g[i].y += g[i].vy;
g[i].lock--;
}
}
// init(PLANET_COUNT);
setInterval(function () {
var w = document.body.clientWidth;
var h = document.body.clientHeight;
maxLineLength = Math.max(30, Math.min(w / 10, h / 10));
canvas.setAttribute('width', w);
canvas.setAttribute('height', h);
canvas.style.width = w + 'px';
canvas.style.height = h + 'px';
step();
}, 30)
</script>